Design surgery-first in facial asymmetry correction with a navigational planning system
Tung-Yiu Wong DDS
Department of Oral and Maxillofacial Surgery
National Cheng Kung University Hospital
Facial asymmetry is common in the orthognathic patients. There is some confusion with the treatment principles as a result of a shortage of diagnostic and planning tool in facial asymmetry. A navigational planning system is a hybrid system to enhance clinicians’ planning capability while preserving their customary practice. It allows direct negotiation between occlusal relationship and skeletal relationship, where clinicians are able to see and adjust the dental arch position and the facial bone positions in real time.
Surgery first has special merits for facial asymmetry correction. 1) The condylar hyperplasia or tumor associated with the asymmetry can be terminated in the first place; 2) The deformity is corrected early; 3) Dental decompensation may be difficult or not necessary. The aims of surgery-first approach for facial asymmetry correction are 1) Restore facial symmetry and harmony; 2) Obtain a correctable postoperative occlusion; 3) Reduce surgical complexity or complications. Because usually there will be no good dental intercuspation, and because good intercuspation does not necessary result in good facial symmetry or harmony, the navigational planning system is used in planning. For simplicity and accuracy, an automated voxel-based median plane- the optimal symmetry planes (OSPs) are used as guides in correcting the skeletal asymmetry.